Liftmaster Security+ keypad won't open door anymore

My Liftmaster Security + keypad has worked well for 7 years. Today it quit opening the door. You can put in the code and it will close the door but won't open it. I replaced the battery with no different result. The keypad will blink for about 15 seconds. I tried to change the password but couldn't. Any suggestions?

I have seen many people with problems with their garage doors but your might be the first of its kind I have encountered. The circuit in the remote might have rusted inside since it has been in use for 7 years. Maybe its time to get a new one? I am sure Liftmaster would have spares available.